Types of powder

In both bag and case charges, the following type of powder are used:

SPD: This is smokeless powder stabilized by the addition of diphenylamine.

SPDN: This is stabilized smokeless powder with the further addition of certain nonvol-atile materials to reduce hydroscopicity and increase service life.

SPCG: This is flahless double-base smoke-less powder containing nitroglycerine and stabilized with carbamite. A new propellant, this one makes only one-half as much smoke as the older flashless powders. Made in the same physical shape as conventional powder, SPCG is chalk white in color and opaque, becoming slightly yellow with age. It contains only one-tenth the volatile solvent contained in pyro powder and is thus less susceptible to ballistic change from towage. SPCG powder is governed by the same stowage regula-tions as SPD, SPDN, etc., except for the surveillance tests.

SPDF: Flashless smokeless powder.

SPDX: Water-dried stabilized smokeless powder.

SPDW: Reworked powder, for target use.